Conventional peanut and other nut butters or spreads consist of a mixture of solid nut particles, liquid oil, flavorants, e.g., a sweetener such as sugar, high fructose corn syrup or honey, and salt, and a stabilizer. Peanut butters typically contain about 50% oil and about 50% solids and have good texture, spreadability and flavor. Other nuts have up to 75% oil and butters made from them have higher oil levels than peanut butter.
High protein and/or reduced fat nut spreads are typically prepared by increasing the level of protein-containing solids in the final product relative to the level of oil. Reduced fat peanut spreads, for example, typically have from about 58% to about 75% solids and from about 25% to about 42% oil.
Unfortunately, increasing the solids level relative to the oil level can have deleterious affects on the quality of the nut spread. For example, higher solids levels can increase the viscosity of the spread making it undesirably stiff (e.g., nonfluid). Spreadability or fluidity is highly sensitive to the oil content of the nut spread; the lower the oil content, the harder the product is to spread. Most nut butters have a biomodal particle size distribution. The addition of non-nut solids, e.g., starches or proteins, reduces the fluidity of the nut spread and can create a polymodal particle size distribution in the finished nut spread (reduced fat nut spreads desirably have a monomodal or bimodal particle size distribution). Solid particles above 20 microns in size create a grittiness sensation in the mouth. Lastly, adding solids which are not from nuts dilutes the nut or peanut flavor.
Past attempts to make nut spreads with desirable fluidity, smooth texture and good flavor but which contain a high level of solids (e.g., greater than about 58%) have not been wholly successful. Efforts to reduce grittiness have resulted in a high viscosity spread. Attempts to reduce viscosity have resulted in nut spreads with less flavor compared to full fat peanut butters. A process taught by Wong et at. utilized a roll milling operation to prepare defatted peanut solids for use in a low fat peanut spread. (See U.S. Pat. No. 5,079,027 issued Jan. 7, 1992.) Another process taught by Walling et al utilized extrusion roasting or a combination of roll milling and high shear mixing to prepare defatted peanut solids to be combined with undefatted peanuts in the preparation of a low fat peanut spread. (See U.S. Pat. No. 5,230,919 issued Jul. 27, 1993.) The use of defatted peanuts and intense lo processing conditions resulted in peanut spreads with inferior flavor compared to full fat peanut butters. Moreover, the roll milling and extrusion roasting processes taught by Wong et al. and Walling et al. are relatively capital intensive for a peanut manufacturing operation.
When whole fat nut pieces or fat containing chips (e.g., chocolate chips) or flavors are added to the low fat nut spread, the overall fat content is increased. When these high fat materials are added for flavor, texture or variety, the fat content of the nut spread needs to be lower than 35% fat to continue to deliver a total low fat content.
A key to making a low fat spread is controlling the viscosity of the butter during processing. If the mixture gets excessively viscous, it cannot be pumped easily and when the mixture is milled excess work is required. The spread can overheat and bum. It is therefore an object of this invention to provide a process for making a nut spread that controls the viscosity during processing by controlling the order of addition of the solid ingredients, particularly by limiting the work applied to the protein mixture.
It is therefore an object of the present invention to provide a process for preparing high protein and/or reduced fat nut spreads which have desirable texture (e.g., are not gritty) and fluidity and which have a nut flavor comparable to that of conventional full fat nut butters and which are low enough in fat to accommodate full fat nut chunks and other fat containing chips, particles and flavors.